<html>
<head>
<style type="text/css">
BODY {
    margin: 0;
    padding: 0;
  }

#wrapper {
    position: relative;
    height: 100%;
    width: 100%;
  }

#header-wrapper {
    position: absolute;
    background-color: #787878;
    height: 80px;
    width: 100%;
  }

#content {
    position: absolute;
    background-color: #ababab;
    width: 100%;
    top: 80px;
    bottom: 50px;
  }

#footer-wrapper {
    position: absolute;
    background-color: #dedede;
    height: 50px;
    width: 100%;
    bottom: 0;
  }
</style>
</head>
    <body>
        <div id="wrapper">
            <div id="header-wrapper">
                <div id="header">
                    <div id="logo-bar">Logo</div>
                </div>
                <div id="nav"></div>
            </div>
            <div id="content">Content</div>
            <div id="footer-wrapper">
                <div id="footer">Footer</div>
            </div>
        </div>
    </body>
</html>